From 601ee769f5ceeab7c71e61806804e4788f279c59 Mon Sep 17 00:00:00 2001
From: Nao Pross <naopross@thearcway.org>
Date: Sat, 5 May 2018 17:13:59 +0200
Subject: Rename class pin to io_pin, add general gpio class, add uart echo

---
 hal/uart.tpp | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 63 insertions(+), 12 deletions(-)

(limited to 'hal/uart.tpp')

diff --git a/hal/uart.tpp b/hal/uart.tpp
index 148ff7d..0ecd615 100644
--- a/hal/uart.tpp
+++ b/hal/uart.tpp
@@ -4,8 +4,8 @@
  *
  * Created on May 2, 2018, 7:05 PM
  * 
- * Note: Templated functions cannot be created outside of a namespace definition
- *       because of a g++ bug in version 4.8.0 on which xc++ is based.
+ * Note: Templated functions inside a namespace cannot be created outside of a 
+ *       namespace because of a g++ bug in version 4.8.0 on which xc++ is based.
  *       See: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480
  */
 
@@ -40,6 +40,19 @@ namespace uart
         return uart::_tx_buffer[dev -1];
     }
 
+    template<unsigned dev>
+    inline bool echo(bool enabled)
+    {
+        static_assert(dev <= devices_count, "invalid device number");
+        _echo[dev -1] = enabled;
+    }
+
+    template<unsigned dev>
+    inline bool echo_enabled()
+    {
+        static_assert(dev <= devices_count, "invalid device number");
+        return _echo[dev -1];
+    }
 
     // read from serial device
     template<unsigned dev>
@@ -51,6 +64,17 @@ namespace uart
         return byte;
     }
 
+    template<unsigned dev>
+    uint8_t read_wait()
+    {
+        while (rx_buffer<dev>().empty());
+
+        uint8_t byte = rx_buffer<dev>().front();
+        rx_buffer<dev>().pop();
+
+        return byte;
+    }
+
 #if 0
     template<unsigned dev>
     std::string read(const unsigned len)
@@ -121,11 +145,21 @@ namespace uart
     template<unsigned dev>
     void write(const std::string &str)
     {
-        // TODO: if size of str is reasonale, push to queue AND THEN send
+        // TODO: if size of str is reasonale, push to queue AND THEN send,
         //       right now on each call the interrupt is enabled and disabled
-        for (const char &c : str) {
-            write<dev>(c);
+        // for (const char &c : str) {
+            // write<dev>(c);
+        // }
+
+        // disable send data flag
+        IEC1bits.U1TXIE = 0;
+
+        for (int i = 0; i < str.size(); i++) {
+            tx_buffer<1>().push(static_cast<uint8_t>(str[i]));
         }
+
+        // enable send data flag
+        IEC1bits.U1TXIE = 1;
     }
 
     template<unsigned dev>
@@ -138,6 +172,13 @@ namespace uart
             write<dev>(*(bptr++));
         }
     }
+
+    template<unsigned dev>
+    void print(const std::string &str)
+    {
+        write<dev>(str);
+        write<dev>("\n\r");
+    }
 }
 
 
@@ -145,8 +186,8 @@ namespace uart
 
 #ifdef DEBUG
 #include "pin.tpp"
-pin<2> led_blue(&LATBbits, &TRISBbits, &PORTBbits);
-pin<3> led_green(&LATBbits, &TRISBbits, &PORTBbits);
+io_pin<2> led_blue(&LATBbits, &TRISBbits, &PORTBbits);
+io_pin<3> led_green(&LATBbits, &TRISBbits, &PORTBbits);
 #endif
 
 void __ISR(_UART_1_VECTOR, IPL1AUTO) usart_1_isr()
@@ -159,23 +200,33 @@ void __ISR(_UART_1_VECTOR, IPL1AUTO) usart_1_isr()
         while (!U1STAbits.URXDA);
         uart::rx_buffer<1>().push(static_cast<uint8_t>(U1RXREG));
 
+        // echo
+        if (uart::echo_enabled<1>()) {
+            // uart::write<1>(uart::rx_buffer<1>().front());
+            IEC1bits.U1TXIE = 0;
+            uart::tx_buffer<1>().push(uart::rx_buffer<1>().front());
+            IEC1bits.U1TXIE = 1;
+        }
+
         IFS1bits.U1RXIF = 0;
 
     } 
     // on each interrupt call, send one character
     else if (IFS1bits.U1TXIF) {
-        // if empty, disable send data flag
-        if (uart::tx_buffer<1>().empty()) {
-            IEC1bits.U1TXIE = 0;
-            return;
-        }
 
+        // disable TX interrupt flag
+        IEC1bits.U1TXIE = 0;
         led_green.toggle();
 
         // write data
         U1TXREG = static_cast<decltype(U1TXREG)>(uart::tx_buffer<1>().front());
         uart::tx_buffer<1>().pop();
 
+        // if not empty, enable tx flag
+        if (!uart::tx_buffer<1>().empty()) {
+            IEC1bits.U1TXIE = 1;
+        }
+
         IFS1bits.U1TXIF = 0;
 
     } else {
-- 
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